Dark energy is no more mysterious than the reason why the expansion of the universe is accelerating. Although space is not a perfect vacuum, the area outside our multi-verse is and, therefore, causes our universe to blow up like a balloon, not from a positive force inside, but from the negative force outside. And the expansion is accelerating because the gravitational pull of galaxies is, by definition, lessening as they grow farther apart. Common sense.

Dark energy is no more mysterious than the reason why the expansion of the universe is accelerating. Although space is not a perfect vacuum, the area outside our multi-verse is and, therefore, causes our universe to blow up like a balloon, not from a positive force inside, but from the negative force outside. And the expansion is accelerating because the gravitational pull of galaxies is, by definition, lessening as they grow farther apart. Common sense.

Can you support your idea with citations?

"The only safe rule is to dispute only with those of your acquaintance of whom you know that they possess sufficient intelligence and self-respect not to advance absurdities; to appeal to reason and not to authority, and to listen to reason and yield to it; and, finally, to be willing to accept reason even from an opponent, and to be just enough to bear being proved to be in the wrong."

Although space is not a perfect vacuum, the area outside our multi-verse is

There is no "outside" our universe. (And no evidence that that there is a mulitiverse).

And if there were, why would it be a vacuum? And if it were, why would it affect all galaxies in the universe, rather than just gas at the edges diffusing into the vacuum? (Clue: a vacuum is not a force.)

It would also suggest that the Earth is in the center of the universe, which seems rather implausible.

So, in conclusion: no.

Common sense.

And that is why we use the scientific method: to get away from "common sense" conclusions which are, almost by definition, wrong.

Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore

Dark energy is no more mysterious than the reason why the expansion of the universe is accelerating. Although space is not a perfect vacuum, the area outside our multi-verse is and, therefore, causes our universe to blow up like a balloon, not from a positive force inside, but from the negative force outside. And the expansion is accelerating because the gravitational pull of galaxies is, by definition, lessening as they grow farther apart. Common sense.

Vacuum does not exert a negative force. To take the balloon analogy, what would cause it to expand if placed in a vacuum is the pressure inside the balloon pushing outward. The pressure pushing out on the skin of the balloon is caused by the kinetic energy of the gas molecules inside and their bouncing off the inside of the balloon's skin.

If you were to take a ball of compressed gas and placed it in a vacuum, the gas molecules would have nothing to contain them and start to spread out. If nothing exists to retard this expansion of the gasses, you will get a constant rate of expansion. With nothing opposing the expansion you get a constant rate and not an accelerating one.

If you then consider the gravitational attraction of the gas molecules, it will work to retard the expansion. This will slow the expansion rate over time. While it is true that as the molecules get further apart from each other this effect will weaken, it will not lead to an acceleration of the expansion but just to a decrease in the deceleration. It's like slowly letting up on the brake while coasting on the level, it will effect how fast the car slows, but will not speed the car up.

So even if we accepted the "universe expanding in a larger vacuum" model of the universe, you don't get an accelerated expansion as you suggest.

But as pointed out, this is not the accepted model for the universe, because in order for that model to match observation, the Earth would have to be at the center of the expansion.